In "Dark Shadows," an otherwise subpar episode of Mad Men this season, Don intentionally leaves Ginsberg's work in a cab before a client presentation. Don's campaign—an awkward and stilted pitch of a devil eating a Snow Cone in hell—was chosen, and he in turn was able to reassert his dominance. The act of sabotage, more befitting of Pete Campbell's scheming ways, confirmed just how personally adrift and professionally impotent Don has become at this point in the series. Ginsberg, meanwhile, is neatly adopting his narrative.

When he first appeared on this season of Mad Men, Ginsberg was as much a cliché on screen as he was token personality in the office. Ginsberg, in that first episode, was manic and frenetic. He belittled Peggy then tried to pass off his apology as a sign of strong character: "I apologized because I'm honest," he told her. But is he? Later, he tells Peggy that he has no family, no one to share his happiness over the new job—and yet the episode ends with his return to a home that he shares with his father, who immediately offers a prayer of thanks and protection for his son's new path.

Ginsberg is continually placed outside the community of SCDP: he refuses to look at grisly crime scene photos that everyone else is gushing to glimpse ("Mystery Date"), he talks a client out of an agreed-upon pitch during a meeting. His separation is at its most extreme in "Far Away Places" when he tells Peggy his origin story during a late night session at the office. It is in this scene that we begin to see how Ginsberg fits into the larger story of Mad Men and, in taking the hero role from Don, embodies its ethos.

Ginsberg is unwilling to accept his true origins. He tells Peggy that he is from Mars, but in fact he was born in a concentration camp and adopted from a Swiss orphanage. Like Don, Ginsberg refuses to accept the truth of his life. He goes about creating an alternate story for himself, and develops the persona to match. His mother, like Don's, died soon after his birth and he became an unwanted child. Like Don, he uses a little lie to get in the door: Ginsberg tells Peggy that he has no family, which is more a manifestation of his fantasy than anything else. And like Don, Ginsberg is a creative genius—perfect for the job he's made for himself.

But while Ginsberg sees himself clearly, Don has lost himself. It's no accident that Ginsberg tells his story to Peggy as he stares directly at a clear reflection of himself in the window of their office. Don, on the other hand, ends the episode as lost as he's ever been—his face is obscured in the reflection of the conference room's glass wall, where Cooper has just blamed him for the creative department's failings. The image of the buildings across the street—the skyscrapers that Don wants to wake up looking at, as he says in "Signal 30"—covers his face and we lose him. From the very beginning of the season, this has been our image of Don.

The thing that truly separates Don and Ginsberg is that Ginsberg has merely invented his alternate history while Don has stolen his. So much of Mad Men is about people trying on different lives. This is also true of advertising in general, and this season has been about the authenticity that the characters bring to their own lives. Roger and Jane get to have a clean break in their relationship and come out mostly unscathed because they can finally be honest with each other about the state of their marriage, an outcome driven as much by LSD as the conversation about truth that precedes their trip. Peggy, meanwhile is sinking farther down in her love life as she struggles to tell Abe what she really wants. These truths aren't the same as the stories the company sells in their ads.

Don can only playact the part of an ad man at this point. In "Lady Lazarus", he acts out a scene about Cool Whip—so complete an imitation of something real that it must be produced in a lab—with his wife. One scene later, he stares down an empty elevator shaft, one step away from taking the LA Law way out. Later, when he acts out the same scene with Peggy, he's doing an impression of himself while Peggy does an impression of Megan.

One would expect that, having shed the secret of his origin to his new bride (and, partially, to his daughter) would have cleared things up for Don. But he's more lost than ever. He's neither Dick nor Don. He is something else entirely now. Don was marked not just by his genius at work but by his very deep secret. That was the source of his power and of his otherworldliness, and it is the reason he had so much power.

In the world of Mad Men, the truth is freeing for everyone—except for Don. His inability to understand and appreciate the Beatles' "Tomorrow Never Knows" in "Lady Lazarus" is a clear indication that Don's time has passed. As America changes in the next few years, Don will forever be stuck as he is now: attempting to be authoritative in an awkward dinner jacket and coming off as a square instead. It's time he passes the torch.